Qualidade de rebordos alveolares preservados e sua influência na estabilidade primária e secundária do implante: resultados preliminares de um estudo clínico-microtomográfico controlado e randomizado

Abstract

This randomized controlled clinical microtomographic trial aimed to compare the bone quality between two different methods of alveolar ridge preservation and to evaluate the primary and secondary implant stability. Twenty patients were randomly divided into two groups following a single tooth extraction: SBC group (n=10), sockets were grafted with alloplastic biphasic calcium phosphate and a pedicle subepithelial connective tissue flap was used for primary closure; and PROV group (n=10), sockets were sealed with an ovate pontic provisional restoration. After 12 months, 11 patients received dental implants, with nine patients lost to follow-up. Bone biopsies were evaluated by microcomputed-tomography (8 μm) to determine cancellous bone characteristics. Insertion torque values (ITV) and initial implant stability quotient (ISQI) were recorded at installation. The ISQ was also recorded 7, 30 and 60 days after the implant was installed. All implants showed uneventful osseointegration. The PROV group presented thicker trabeculae (0.17±0.03) compared to the SBC group (0.11±0.03; p 0.03). Trabeculae bone was more anisotropic in the PROV group (0.3±0.08) compared with the SBC group (0.1±0.07; p 0.01). The PROV group presented less bone surface (26.02±10.36) than the SBC group (40.09±10.94; p 0.05). Also, PROV showed higher ISQI (72.3±21) than SBC (67±3.9; p 0.05). The characteristics of the trabecular bone differed between the two alveolar ridge preservation methods and the both preservation methods gave satisfactory results with regard to implant placement, and both resulted in high values for ITV and ISQ.